The present invention relates to a new and improved steering system in which lash is taken up when the steering system is in an initial or straight-ahead condition.
A known vehicle steering system includes a steering wheel and a power steering control valve which are interconnected by a linkage assembly. Upon rotation of the steering wheel, the linkage assembly actuates the steering control valve to effect operation of a power steering motor to turn steerable vehicle wheels. When the vehicle wheels have been turned to an extent corresponding to the extent of rotation of the steering wheel, a feedback linkage connected between the power steering motor and the steering control valve is effective to operate the steering control valve to its initial or unactuated condition. When this occurs, operation of the power steering motor is interrupted.
When the vehicle is proceeding straight down a road, lash between components of the steering system may result in the steering system tending to move away from an on-center or straight-ahead condition. When this occurs, the vehicle may tend to wander, that is to turn slightly, relative to the centerline of the road. This may be disconcerting to a driver of the vehicle.
An improved apparatus for use in turning steerable vehicle wheels includes devices which take up lash between components of the apparatus. One of the devices may be connected with the steering system adjacent to the steering wheel. The other device may be connected with a power steering motor. The two devices urge components of the steering system to move in opposite directions relative to each other to take up lash between components of the steering system. The two devices which take up lash between the components of the steering system may be a first spring which is connected with the steering system at a location adjacent to a steering wheel and a second spring which is connected with a power steering motor.